1. Field of the Invention
This invention relates to a steering wheel in which a pad portion is formed integrally with the remaining covering portion of the steering wheel.
2. Discussion of Prior Art
Generally, a steering wheel comprises an annular ring portion, a pad portion, provided generally centrally of the ring portion, and a plurality of spoke portions extending from the ring portion toward the center of the ring portion. A ring portion metal core is embedded in the ring portion, and a spoke portion metal core is embedded in each of the spoke portions. The ring portion metal core and the spoke portion metal cores are covered with a covering portion made, for example, of a foamed polyurethane. A boss plate for mounting the steering wheel to a steering shaft is connected to the spoke portion metal cores at a position beneath the pad portion.
Recently, there has been proposed a type of steering wheel (Japanese Utility Model Unexamined Publication No. 2-133955) where the covering and pad portions are molded integrally with each other, thereby eliminating the boundaries between the covering portion and the pad portion. With this arrangement, the covering portion and the pad portion are integral with each other, thereby enhancing the design of the steering wheel. In the steering wheel disclosed in the above publication, in order to prevent the pad portion from being broken apart and being scattered when an air bag device is operated, an insert is embedded in the pad portion. The insert is fixed to a foamed resin member formed on the metal core.
In the above conventional steering wheel, however, because the insert is fixed to the foamed resin member, when the pad portion opens upon expansion of the air bag, there is a possibility that the insert may disengage from the fixing portion, so that the pad portion, the foamed resin member for fixing purposes, and other pieces are scattered.